I didn't play all levels ATM but here's what I have to say about the game. Sorry in advance if I make a suggestion about things that are in the part I didn't play :-) But first, nice addictive gameplay! Reminds me about Pipe Dream and Sokoban!
There could some block rotating device in harder levels.
I had some issue for pushing blocks beside each other. If we are supposed to be able to do so, maybe considering activating the push from a little further away from the blocks.
I think the player could jump the height of 1 cube. Like that, you could remove most of the stairs in the game field :-)
Maybe the ball gathering lights could be more visible. Like a screen beside the exit door, or even directly on it.